This invention relates in general to a method and apparatus for controlling the heating and cooling functions of a heat pump system to thereby effectively regulate the temperature within a controlled environment. In particular, this invention relates to a low-voltage control panel that electrically couples the low-voltage control sections of the operable components of a heat pump system so that the operating mode of the system is determined by the monitored temperature of the controlled environment.
A heat pump heating and cooling system normally includes an indoor thermostat which monitors the temperature of the environment being controlled, an outdoor heat pump which is operable to heat and cool the environment being controlled, and an indoor heating unit which is operable to supplement the heating capacity of the heat pump.
The heating efficiency of an outdoor heat pump is directly related to the outdoor temperature. In other words, the heating capacity of the heat pump decreases as the outdoor temperature drops. Since the heating capacity of a heat pump is temperature dependent and since the heating load in most areas is greater than the cooling load, the heat pump system is normally equipped with an indoor heating unit to supplement the heating capacity of the outdoor heat pump. Typically, the indoor heating unit is comprised of resistance heaters that produce heat by passing an electric current through a resistant. This method of heat generation is highly inefficient and extremely costly to operate. A more efficient and less costly method for supplementing the heating capacity of the outdoor heat pump is to use a fossil fuel furnace. While a fossil fuel furnace is more efficient and economical than resistance heaters, it is not as efficient or economical as the heat pump itself. Therefore, it is desirable to make maximum use of the outdoor heat pump in order to improve the overall operating efficiency of the heating system thereby minimizing heating costs. As the availability of fossil fuels decreases and as the price of these fuels increases, it will become even more critical from an environmental and cost standpoint to make the most efficient use of our remaining fuel reserves.
My invention provides a unique method and apparatus for coupling and controlling the operable components of a heat pump system in a manner that makes the most efficient use of the components of the heating system. In particular, the present invention comprises a low-voltage heat pump control panel that is of standard design and suitable for use in a heat pump system comprising an indoor thermostat, an outdoor heat pump and an indoor fossil fuel furnace. The low-voltage control panel of the present invention utilizes a single master switching relay to interconnect the operating components of the system so that the operating mode of the system is selected in accordance with the temperature within the controlled environment. By using the temperature of the controlled environment to select the operating mode of the system. The operable components of the heating system can be coupled and controlled in a highly efficient manner at a relatively low cost.
The low-voltage control panel of my invention is further arranged to effectively remove the outdoor heat pump from the system if the unit experiences operating problems. An emergency heat switch controls the switching state of the master switching relay. Closure of the emergency heat switch causes the master switching relay to change states thereby placing the system in the emergency heat mode. In the emergency heat mode, the outdoor heat pump is effectively removed from the system and full heating responsibility is transferred to the fossil fuel furnace.
It is therefore an object of the present invention to provide a method and apparatus for interconnecting the low-voltage control sections of the heating and cooling components of a heat pump system comprising an indoor thermostat for monitoring the temperature of the controlled environment, an outdoor heat pump for heating and cooling the controlled environment and an indoor fossil fuel furnace for supplementing the heating capacity of the heat pump.
A further object of the present invention is to provide a method and apparatus for operably coupling the low-voltage control sections of the heating and cooling components of a heat pump system which is of standard design and can be manufactured and sold at a relatively low cost.
A further object of the present invention is to provide a low cost method and apparatus for interconnecting the low-voltage control sections of the heating and cooling components of a heat pump system which efficiently controls the overall operation of the system.
Another object of the present invention is to provide a low cost and highly efficient method and apparatus for interconnecting the low-voltage control sections for the heating and cooling components of a heat pump system that selects the operating mode of the system in accordance with the temperature of the controlled environment.
An additional object of the present invention is to provide a low cost and highly efficient method and apparatus for interconnecting the low-voltage control sections of the heating and cooling components of a heat pump system which use a single master switching relay having two switching states one of which effectively removes the outdoor heat pump from the system.
It is a further object of the present invention to provide a low cost and highly efficient method and apparatus for interconnecting the low-voltage control sections of the heating and cooling components of a heat pump system which includes an emergency heat switch that is operable to control the switching state of the master control relay.
Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description of the drawings.